This invention relates to hot bowls for cigarette lighters, particularly of the type mounted on motor vehicles, and in particular relates to the system for fixing the spiral resistance element into the hot bowl.
Various methods of fixing the resistance element are known in the art, one of which uses an elastic ring which compresses the spiral against the inner wall of the hot bowl. Apart from the increased cost due to the elastic ring, this method of fixing involves an operation which is not easy to execute automatically, namely the insertion of the elastic ring into the wall of the hot bowl. The most usual system for fixing the end of the resistance element to the interior of the hot bowl is welding. However this system is subject to certain drawbacks. The first is that the welding can present problems of current passage through the insulating layer of the resistance element. The second problem, and perhaps the more important, is that because of the hardening procedure normally undergone by the wall of the hot bowl the welding cannot be reliably effected, with the result that because of the continuous temperature variations the resistance element becomes detached during the product life.